Various fasteners have been described which provide compression to a surface. Standard screws provide an anchoring of the screw through the shear force exerted by the thread against the walls of the bore in which it is embedded. The head of the screw provides compression against the material. In situations where threads cannot purchase the material surrounding the bore, jackets surrounding the threads of the screw are often utilized. The jacket is designed to expand in the bore of the material and provide anchoring for the screw threads. Known screw devices cannot deliver a precise level of load to the cable or tendon tension. At present, when a cable is attached to a screw, or a sheath around the screw, and the screw is turned, the cable or sheath are not stabilized against rotation with respect to the substrate to which the screw is engaged
One type of known compressive bolt device consists of wings which provide compression to a surface of the material in which the device is mounted. Thus both sides of the bolt are compressing material as opposed to screws where one side is acting in shear. These devices generally are not wholly removable and require the wing side of the device to be left within or on the surface of the material within which the device was installed, when the bolt portion is removed.
Another type of known compressive bolt device includes winged bolts in which the device is wholly removable following use. Some of these devices are disclosed in U.S. Pat. No. 4,409,974 issued in 1983, which covers a bone-fixating surgical implant device.